The invention relates to a vehicle with a wiring harness, which ties a group of ground conductors into a bundle, and a method for the production of the wiring harness.
The physical electrical system of a modern vehicle has a complex architecture. It consists of an electrical grid that is designed as a wiring harness. This means that various cables such as ground conductors or supply lines are combined into bundles that form the wiring harness, also known as a cable harness.
The electrics/electronics of a modern vehicle with a partially electrified drive train has an even higher degree of complexity. This also concerns the cable harness and is explained in German patent document DE 102010042963 A1, for example.
The object of the invention is to provide an improved vehicle with a cable tree that ties a group of ground conductors into a bundle, and with an essentially electrical non-conductive body as well as a method for the production of the wiring harness.
This and other objects are achieved according to the invention by providing a vehicle with a cable harness and with an essentially electrically non-conducting body, wherein the vehicle includes at least one ground point, at least one bus bar is assigned to the cable harness, and the at least one bus bar is assigned to the at least one ground point. The ground point is electrically connected with the bus bar, and the bus bar is mechanically fixed in the vehicle. A method of producing the cable harness is also provided.
The invention teaches that the vehicle includes at least one ground (mass) point and the cable harness includes at least one bus bar that is assigned to the at least one ground point, wherein the ground point is electrically connected with the bus bar and the bus bar is mechanically fastened in the vehicle.
In this manner, components of the cable tree are electrically connected with the ground point in the vehicle by means of the bus bar in order to bring about an electrical ground connection with the ground conductors that are connected with the components of the vehicle.
In vehicles with a non-conductive body, the same is not suitable for use as a return conductor for electrical consumers. Ground conductors have to be laid across longer paths and in bundles with a larger number of ground conductors to a few ground points or even only a single ground point than with a vehicle with a metallic body. Consequently, depending upon the vehicle equipment, a particularly high number of ground conductors is to be connected electrically to the ground on this ground point. A space saving and easy to fit bus bar is therefore particularly advantageous.
This particularly applies to a vehicle with a body, for example, which is essentially produced from carbon fiber reinforced plastic.
According to a preferred embodiment of the invention, the cable harness ties a group of ground conductors into a bundle, which are run through a bundle of the cable tree to the bus bar that is assigned to the group of ground conductors and is electrically connected with it.
This is advantageous because for producing the ground connection, it is not necessary that each individual ground conductor must be provided with a connector, which in turn is then connected with a ground strip or similar to serve as mating connector. The use of a bus bar facilitates savings in installation space, material, and installation costs.
Furthermore, a method for producing a cable harness for a vehicle according to the invention is proposed in particular for producing an electrical contact between the group of ground conductors of the cable harness and the at least one bus bar of the cable harness, which includes the following steps:                a) Providing the cable harness bundle with the group of ground conductors;        b) Providing a bundle template for the cable harness bundle and a first conductor template for the group of ground conductors;        c) Inserting the cable harness bundle into the bundled template and inserting each individual ground conductor of the group of ground conductors into a conductor guide element assigned to the related ground conductor of the first conductor template and fixing the group of ground conductors with a second conductor template.        
The advantage of this method is that the ground conductors can be present in different lengths. The bundle template can provide guide elements for the bundle, onto which the bundle is to be attached. These could also be adjustable variably to match the template to the bundle diameter, and to be able to process various cable harness bundles with one bundle template. The conductor guide elements of the first conductor template are preferably designed as swages or as grooves, wherein one guide element exists for each of the ground conductors.
Further steps of the process are:                d) Trimming, i.e. cutting, the group of ground conductors with a trimming element;        e) Stripping each ground conductor of the group of ground conductors with a stripping unit, in order to expose a group of stranded wires from the group of ground conductors;        f) The ground conductors are cut to a defined length, and the stranded wires of the ground conductors are exposed; Then these steps follow:        g) Providing a first bus bar element;        h) Inserting each individual stranded wire of the group of stranded wires into one stranded wire guide element assigned to the related ground conductor of the first bus bar element;        i) Providing a second bus bar element and connecting the first bus bar element with the second bus bar element for producing the bus bar.        
The bus bar facilitates contacting the group of stranded wires in conjunction with the bus bar. It describes the process for cost-effective and easy to fit steps for producing a wire harness with at least one bus bar for ground conductors. A wound or tubular cable harness bundle with the ground conductors serves as a starting base. On a template, the group of ground conductors that consists of insulated ground conductors of various lengths is trimmed, stripped, and connected with the bus bar.
According to a further variant of the method, the cable harness bundle to be provided includes a branch point, wherein the group of ground conductors is run out from the cable harness bundle at the branch point, and on which the bundled template to be provided includes an isolation port for the cable harness bundle and the group of ground conductors.
In this instance, the cable harness bundle at the branch point is run through the isolation port of the template, so that a part of the template isolates the group of ground conductors from the at least one other isolation piece of the cable harness bundle for further processing.
In this way, an optionally branched cable harness with possibly multiple bus bars can be produced.
The invention is based upon the considerations stated below.
In a typical vehicle cable harness, cable cores with the same contacting, such as ground conductors, are normally crimped together with one female disconnect and then plugged by means of the end fittings generated by the crimping into line collectors (with the selected example of ground conductors into so-called ground strips) group by group.
Such ground strips can be screwed or connected onto body-mounted ground bolts at any places of a vehicle having a metal body. The chassis ground connection of the vehicle, which is typically formed by the negative battery terminal, exists via the ground bolts and via the metallic conductive vehicle body. Because of the potential plurality of ground bolts in the vehicle, the ground conductors must usually be run only across a “short” distance in the vehicle.
This is not possible with a vehicle with a plastic body. Because of the inadequate electrical conductivity of the body, all and/or a plurality of ground conductors must be run to a central collection point and/or to central collection points. This is problematic if crimped ground conductors and ground strips are used because this means a plurality of female disconnects on an outlet piece of the cable harness as well as a plurality of ground strips with qualified screw connections on the body. This requires a high effort in terms of the weight, the required installation space, production engineering as well as the assembly and ease of maintenance. One of the problems to be solved for cable harnesses in plastic bodies is to reduce the material, assembly, integration cost and therefore the expense required for the connection of ground connectors.
A solution based upon a bus bar is provided. The bus bar is based upon a template system and can be integrated into the vehicle, which saves installation space and facilitates an efficient assembly of the ground connection of the ground conductors.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.